#include<bits/stdc++.h>
using namespace std;

const int nmax=300+5,mod=1e9+7;

int n,inp[nmax];

int dp[nmax][nmax*nmax];

int rec(int pos,int delta)
{
    if(pos==n)
    {
        //cout<<delta<<" "<<inp[n]<<endl;

        if(delta>inp[n])return 0;

        if(delta==inp[n]||delta==0)return 2;

        return 3;
    }

    if(dp[pos][delta]!=-1)return dp[pos][delta];

    int ret=rec(pos+1,delta+inp[pos]);

    ret=ret+rec(pos+1,delta);

    if(ret>=mod)ret=ret-mod;

    ret=ret+rec(pos+1,abs(delta-inp[pos]));

    if(ret>=mod)ret=ret-mod;

    dp[pos][delta]=ret;
    return ret;
}
int main()
{
    freopen("duel.in","r",stdin);
    freopen("duel.out","w",stdout);

    scanf("%i",&n);
    for(int i=1;i<=n;i++)scanf("%i",&inp[i]);

    memset(dp,-1,sizeof(dp));

    printf("%i\n",rec(1,0));

    return 0;
}